The Chesapeake Bay Program’s Scientific and Technical Advisory Committee (STAC) is administered by the CRC and funded through a cooperative agreement with the Chesapeake Bay Program (CBP) Partnership – currently spanning the period 2016-2022. The CRC has had a long-standing role of administering all activities of STAC, an active committee with 38 members from academic and scientific institutions around the watershed.
STAC Response to COVID-19: Challenges and Opportunities
While COVID-19 restrictions will prevent STAC from meeting in person in the near future, STAC Staff and members have been exploring the advantages of virtual meetings, workshops, and project planning. Virtual meetings present unique challenges, as well as new opportunities to engage with STAC and the CBP Partnership. Web conferencing services provide interactive digital tools such as polling, instant ‘reactions’, file sharing, and ‘breakout groups’. With STAC members from all over the Bay region, virtual meetings will bring together science and technical experts while reducing STAC’s carbon footprint. Last year, STAC members traveled an estimated 33,000 miles to attend quarterly meetings and workshops. If we assume all STAC members have average to medium cars with 21 mpg fuel economy, STAC business emitted as much as four typical passenger vehicles in 2019. This past March, the STAC quarterly meeting was remote due to social distancing measures. Working from a conference room on the Smithsonian Environmental Campus with a small number of CRC and CBP partner staff, our March meeting emissions costs were 3.4% of last year’s total emissions.
STAC Staff continues to conduct extensive research on web conferencing services and strategies in order to maintain the productivity of the committee, and we look forward to continuing our work to bring the latest science to the Chesapeake Bay management community.
STAC Update
STAC held its final quarterly meeting of FY2019 March 10-11, 2020 via Zoom. Members continued to work on Achieving Water Quality Goals in the Chesapeake Bay: An Assessment of System Response and Science Needs (STAC Scientific Gap Analysis, often referred to as SGA). This effort brings together the varied expertise from STAC membership to assess important system limits, knowledge gaps, and research needs to facilitate future dialogue related to the feasibility and consequences of post-2025 policy choices.
STAC Executive Secretary, Denice Wardrop and the STAC-CBP Liaison, Gary Shenk, presented a new procedure and strategy for STAC workshops and reports. They brought forth new communication strategies, policies for increased coordination with CBP workgroups and Management Board, and guidelines for stronger and more actionable recommendations. STAC members were supportive and we will be moving forward in incorporating this new process for FY2020 workshops and STAC products.
Presentations and more information will be made available on the March Meeting Page.
STAC released an RFP for FY2020 workshops in December 2019 and received 3 proposals. During the March quarterly meeting STAC members reviewed the initial scores and comments and voted to approve the 3 proposals. Proposals #2 and #3 were conditionally approved, with the expectation that the workshop proposers will differentiate and coordinate between the two, with assistance from STAC Staff and Gary Shenk. Planning for FY2020 workshops will begin June 1, 2020.
- Understanding Genetics for Successful Conservation and Restoration of Resilient Chesapeake Bay Brook Trout Populations
- Advancing Regenerative Agriculture: Exploring Barriers and Incentives to BMP Adoption
- Overcoming the Hurdle: Addressing BMP Implementation Through a Social Science Lens
STAC has approved the following dates for their 2020 quarterly meetings. All dates are subject to change in response to COVID-19 precautions and time needed to complete the SGA effort.
- June 11, 2020
- September 15-16, 2020
- December 14-15, 2020
On March 5-6, 2020, STAC sponsored a workshop titled “Incorporating Freshwater Mussels in the Chesapeake Bay Partnership” at the Chesapeake Bay Foundation Philip Merrill Center in Annapolis, MD. This two-day workshop synthesized the current knowledge of how freshwater mussels could be best used in support of Chesapeake Bay Program Goals and Outcomes. More information can be found on the workshop webpage.
Information regarding recent workshops- including agendas, presentations, and reports (as they become available) can be found on the workshop homepage.
STAC has one remaining workshop for FY2019. Information regarding upcoming workshops can be found on the future workshops homepage.
- Satellite Image Integration for the Chesapeake Bay SAV Monitoring Program: Final Session—Postponed until further notice
STAC recently released two reports. STAC publications can be found here.
- Increasing Effectiveness and Reducing the Cost of Nonpoint Source Best Management Practice (BMP) Implementation: Is Targeting the Answer?
- Assessing the Environment in Outcome Units (AEIOU): Using Eutrophying Units for Management:
Several workshop steering committees are in the process of drafting activity reports and other workshop outcomes that will be distributed to the Partnership over the next few months. More information on recent workshop reports can be found on the STAC past workshop webpage.
STAC Climate Synthesis Update: Quantifying the impacts of past and future climate and eutrophication on the dynamics of dissolved oxygen in the shallow waters of Chesapeake Bay
Jeremy Testa
University of Maryland Center for Environmental Science
Chesapeake Biological Laboratory
We have primarily focused on the analyses suggested following our Synthesis Team/Steering Committee meeting on January 13-14 2020. This includes statistical analysis (CART, GAM) to determine climate and biogeochemical controls on daily oxygen depletion metrics, (b) computing metrics of ecosystem metabolism (e.g. primary production, respiration) from each station’s oxygen time series, and (c) assembling and collating the data necessary to perform these analyses. We worked with Breck Sullivan and CBP staff to assemble the climatic data we need to associate changes in dissolved oxygen with climate variables. Using the North American Land Data Assimilation System (NLDAS), we obtained spatially-resolved precipitation, air temperature, and wind speed data that will help us discern how climate variables associated with dissolved oxygen variability. In addition, we obtained estimates of photosynthetically active radiation (PAR) from the European Centre for Medium-Range Weather Forecasts system (using ERA5). The ERA5 product provides spatially-resolved estimates of PAR in the Chesapeake Bay region, which we can use to understand how daily changes in PAR impact the photosynthesis-respiration cycle and hypoxia vulnerability. We are validating ERA5 PAR estimates with several local PAR records (Jug Bay NERR, Chesapeake Biological Laboratory, Horn point Laboratory) to ground truth the product, and initial comparisons are favorable
We have performed a wide variety of analysis of shallow water dissolved oxygen data to quantify hypoxia duration, tidal impacts on oxygen variability, and climatic and biological controls on oxygen variability. Below, we highlight three of these ongoing efforts.
(a) Wind-induced air-sea exchanges and biological control on dissolved oxygen: We have begun a series of analyses at test locations to understand and quantify interactions between climatic and biological variables in controlling oxygen surplus and declines. Wind-speed is well-known to control air-sea exchanges of oxygen, where high wind speeds lead to high air-water gas exchange, which pushes dissolved oxygen to equilibrium with the atmosphere. Under air-saturated conditions, oxygen is sufficient for habitat for most organisms. Using the Chesapeake Biological Laboratory pier as a test location, we computed the oxygen excess (defined as the observed O2 minus the air-saturated O2) and found that the oxygen excess was strongly related to wind speed on 15-minute to weekly time scales. At low wind speeds, which are common at this location, oxygen tends to deviate from air-saturation substantially, and daily excesses in oxygen (supersaturation) are associated with high chlorophyll (Figure 2, bottom right), indicating that high productivity actually increases oxygen in the shallow, well-mixed sites. We will apply this method across all other stations to identify patterns of productivity that relate to high and low oxygen extremes.
(b) We have also used a numerical approach to remove the tidal signal (M2 – primary lunar, S1 – primary solar) from diurnal oxygen data, allowing us to isolate oxygen changes associated with biological and physical responses to external forces. We have applied this approach to three test stations before applying it Bay wide.
(c) We have also developed CART models that statistically identify significantly different groups of oxygen conditions associated with different magnitudes of controlling variables (Figure 4). We have applied this approach to three test stations thus far, and used tide-corrected oxygen conditions, measured (raw) oxygen concentrations, and daily computed hours of hypoxia as independent measures of oxygen. These models provide a single framework to determine the most significant controlling factors (e.g., PAR, temperature, precipitation) at a given station. For example, a test of this approach in Monie Bay reveals that water temperature and salinity are the primary controls on DO saturation (after tidal correction), especially when considering a three day lag (PAR is important without lags). Here, DO saturation is lower (tide-corrected residual DO saturation = -1.21%) at water temperatures above 20.8 degrees C and at higher salinity. Additional work will help to apply this approach across all stations and to interpret the mechanisms behind these statistical results.
Products to date and future activities: We have generated a substantial collection of numerical analysis tools that quantify biological and climatic control on dissolved oxygen in shallow waters. We have applied these tools to a subset of stations, and will soon apply these tools across all ConMon stations in Maryland. We continue to collaborate with CBP staff to share tools and co-organize research to analyze the shallow water data toward better understanding habitat and criteria attainment and how they have/will change under recent and future conditions. After a break during the COVID-19-related changes in work structures, we will resume communication with our steering committee in May 2020.